# javaee-test-oop

**Repository Path**: ChalkyCrystal/javaee-test-oop

## Basic Information

- **Project Name**: javaee-test-oop
- **Description**: OOP回顾
- **Primary Language**: Java
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 205
- **Created**: 2026-03-09
- **Last Updated**: 2026-03-09

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# 面向对象程序设计回顾
## 一、类的定义与使用
### 1. 声明Point类
1)  添加两个整型属性`x`,`y`
2)  提供构造函数`Point()`,`Point(int x,int y)`和`Point(Point p)`

```java
public class Point {
    private int x;
    private int y;

    public Point() {
        this.x = 0;
        this.y = 0;
    }

    public Point(int x, int y) {
        this.x = x;
        this.y = y;
    }

    public Point(Point p) {
        this.x = p.x;
        this.y = p.y;
    }

    public int getX() {
        return x;
    }

    public void setX(int x) {
        this.x = x;
    }

    public int getY() {
        return y;
    }

    public void setY(int y) {
        this.y = y;
    }

}
```

### 2. 声明Rectangle类
1) 添加四个属性：`Point ptTopLeft`, `Point ptTopRight`, `int width`,`int height`
2) 为Rectangle类提供构造函数`Rectangle()`,`Rectangle(Point topleft,int hight,int width)`
3) 为Rectangle类添加并实现`double perimeter()`,`double area()`,`void draw()`方法

```java
public class Rectangle implements IShape {
    private Point ptTopLeft;
    private Point ptTopRight;
    private int width;
    private int height;

    public Rectangle() {
        this.ptTopLeft = new Point();
        this.ptTopRight = new Point();
        this.width = 0;
        this.height = 0;
    }

    public Rectangle(Point topleft, int height, int width) {
        this.ptTopLeft = new Point(topleft);
        this.height = height;
        this.width = width;
        this.ptTopRight = new Point(topleft.getX() + width, topleft.getY());
    }

    @Override
    public double perimeter() {
        return 2 * (width + height);
    }

    @Override
    public double area() {
        return width * height;
    }

    @Override
    public void draw() {
        System.out.println("绘制矩形：");
        System.out.println("左上角点：" + ptTopLeft);
        System.out.println("右上角点：" + ptTopRight);
        System.out.println("宽度：" + width + "，高度：" + height);
        System.out.println("周长：" + perimeter() + "，面积：" + area());
        System.out.println("------------------------");
    }
}
```

### 3. 测试Rectangle类
## 二、	类与接口
### 1. 声明IShape接口，添加三个接口方法`double perimeter()`,`double area()`,`void draw()`

```java
public interface IShape {
    double perimeter();
    double area();
    void draw();
}
```

### 2. 声明Circle类实现IShape接口
1)	添加两个属性：`Point ptCenter`,`int radius`
2)	提供构造函数`Circle(Point center,int r)`
3)	实现IShape的三个接口方法`double perimeter()`,`double area()`,`void draw()`

```java
public class Circle implements IShape {
    private Point ptCenter;
    private int radius;

    public Circle(Point center, int r) {
        this.ptCenter = new Point(center);
        this.radius = r;
    }

    @Override
    public double perimeter() {
        return 2 * Math.PI * radius;
    }

    @Override
    public double area() {
        return Math.PI * radius * radius;
    }

    @Override
    public void draw() {
        System.out.println("绘制圆形：");
        System.out.println("圆心：" + ptCenter);
        System.out.println("半径：" + radius);
        System.out.println("周长：" + String.format("%.2f", perimeter()) 
                + "，面积：" + String.format("%.2f", area()));
        System.out.println("------------------------");
    }
}
```

### 3. 声明Triangle类实现IShape接口
1)	添加三个属性：`Point ptA`,`Point ptB`,`Point ptC`
2)	添加三个只读属性：`double edgeA`,`double edgeB`,`double edgeC`
3)	提供构造函数`Triangle(Point ptA,Point ptB,Point ptC)`
4)	实现IShape的三个接口方法`double perimeter()`,`double area()`,`void draw()`

```java
public class Triangle implements IShape {
    private Point ptA;
    private Point ptB;
    private Point ptC;

    private double edgeA; // BC边
    private double edgeB; // AC边
    private double edgeC; // AB边

    public Triangle(Point ptA, Point ptB, Point ptC) {
        this.ptA = new Point(ptA);
        this.ptB = new Point(ptB);
        this.ptC = new Point(ptC);
        calculateEdges();
    }

    private void calculateEdges() {
        // 两点间距离公式：√[(x2-x1)² + (y2-y1)²]
        this.edgeA = Math.sqrt(Math.pow(ptC.getX() - ptB.getX(), 2) 
                + Math.pow(ptC.getY() - ptB.getY(), 2));
        this.edgeB = Math.sqrt(Math.pow(ptC.getX() - ptA.getX(), 2) 
                + Math.pow(ptC.getY() - ptA.getY(), 2));
        this.edgeC = Math.sqrt(Math.pow(ptB.getX() - ptA.getX(), 2) 
                + Math.pow(ptB.getY() - ptA.getY(), 2));
    }

    public double getEdgeA() {
        return edgeA;
    }

    public double getEdgeB() {
        return edgeB;
    }

    public double getEdgeC() {
        return edgeC;
    }

    @Override
    public double perimeter() {
        return edgeA + edgeB + edgeC;
    }

    @Override
    public double area() {
        double s = perimeter() / 2;
        return Math.sqrt(s * (s - edgeA) * (s - edgeB) * (s - edgeC));
    }

    @Override
    public void draw() {
        System.out.println("绘制三角形：");
        System.out.println("顶点A：" + ptA + "，顶点B：" + ptB + "，顶点C：" + ptC);
        System.out.println("边长A：" + String.format("%.2f", edgeA) 
                + "，边长B：" + String.format("%.2f", edgeB) 
                + "，边长C：" + String.format("%.2f", edgeC));
        System.out.println("周长：" + String.format("%.2f", perimeter()) 
                + "，面积：" + String.format("%.2f", area()));
        System.out.println("------------------------");
    }
}
```

### 4. 改造一中的Rectangle类，使之实现IShape接口

### 5. 声明ShapeManager类
1)	添加只读属性`List<IShape> shapes`
2)	添加`addShape(IShape shape)`方法，实现将参数shape对象添加到shapes列表中
3)  添加`delShape(IShape shape)`方法，实现将参数shape对象从shapes列表中删除
4)	添加`drawShapes()`方法，实现shapes列表中所有shape元素的绘制

```java
import java.util.ArrayList;
import java.util.List;

public class ShapeManager {
    private final List<IShape> shapes;

    public ShapeManager() {
        this.shapes = new ArrayList<>();
    }

    public List<IShape> getShapes() {
        return new ArrayList<>(shapes);
    }

    public void addShape(IShape shape) {
        if (shape != null && !shapes.contains(shape)) {
            shapes.add(shape);
            System.out.println("添加形状成功！");
        } else {
            System.out.println("形状为空或已存在，添加失败！");
        }
    }

    public void delShape(IShape shape) {
        if (shapes.contains(shape)) {
            shapes.remove(shape);
            System.out.println("删除形状成功！");
        } else {
            System.out.println("形状不存在，删除失败！");
        }
    }

    public void drawShapes() {
        System.out.println("\n===== 开始绘制所有形状 =====");
        if (shapes.isEmpty()) {
            System.out.println("暂无形状可绘制！");
        } else {
            for (IShape shape : shapes) {
                shape.draw();
            }
        }
        System.out.println("===== 绘制完成 =====\n");
    }
}
```

### 6. 测试代码

```java
public static void Main(String[] args){
	ShapeManager shapeManager=new ShapeManager();
	Rectangle rect=new Rectangle(new Point(10,10),100,200);
	Triangle tri=new Triangle(new Point(0,10),new Point(50,50),new Point(150,0));
	Circle cir=new Circle(new Point(100,100),100);
	shapeManager.addShape(rect);
	shapeManager.addShape(tri);
	shapeManager.addShape(cir);
	shapeManager.drawShapes();
	shapeManager.delShape(rect);
	shapeManager.drawShapes();
}
```